The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which, in and of themselves, may also be inventions.
Wavefront sensors for ophthalmic applications are generally bulky and stand-alone desktop instruments. Although there have been attempts to integrate a wavefront sensor with an ophthalmic instrument such as a LASIK system (see for example, U.S. Pat. No. 6,685,319), a fundus camera (see for example, U.S. Pat. No. 6,572,230), and a confocal scanning laser ophthalmoscope (see for example, U.S. Pat. No. 7,057,806), these integrations are generally not aimed at maintaining the original ophthalmic instrument intact with the wavefront sensor as a separate compact module attached to or integrated with the ophthalmic instrument.